The present invention relates to a track searching method and drive in which an optical pick-up, which reads out an information recorded on a track of an optical disk or a magneto optical disk and the like (hereinafter generically referred to an optical disk) is moved to an objective track.
It is conventionally known that an optical disk drive reads out an information recorded on a track of optical disk, such as CD-ROM, with an optical pick-up, by carrying out track searching where the optical pick-up jumps to an objective track, an absolute time to reach the object track is given as a searching order, the number of tracks is detected by a difference between the given absolute time and an absolute time of a track on which the optical pick-up presently located and, in accordance with the detected number of tracks, the optical pickup jumps. Here, it is supposed that a linear velocity of the optical disk is predetermined value and the number of tracks is detected. However, actually, since the linear velocity is not constant, the detected number of tracks contains error. To revise the error, when a new optical disk is set on the optical disk drive, a revising coefficient is calculated by predetermined learning. And upon track searching, the detected number of tracks to be jumped is multiplied by the predetermined revising coefficient. In accordance with the revised value, the optical pick-up is made to jump.
However, in the above-mentioned track searching method wherein the error revised by the predetermined revising coefficient, generally, since the moving characteristic of a servo system for the pick-up is non-constant in every optical disk drive, in track searching in every optical disk drive, the error is left. So, the error can not be precisely revised.